Process of producing electrical heating devices.



E. L.' WlE-GAND.

PROCESS OF PRODUCING ELECTRICAL HEATING DEVICES. APPLICATION FILED JULY I3, I914.

2 BHEETfi-SHEET 1.

Patented Apr. 20, 1915.

E. L. WIEGAND. PROCESS OF PRODUCING ELECTRICAL HEATING DEVICES.

VAPPLICATION FILED JULY13| I914. 1,136,076, Patented Apr. 20, 1915 2 SHEETS-BEEBT-Z.

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WTNEssEs INVENTOR Arrivirs heating device; Fig. 3 is a or appliance ED STATES rA'rnN'r orrrcn.

nnwm it wrneann, or CANAL novnn, OHIO.

PROCESS OF PRODUCING ELECTRTGAL HEA'1ING DEVICES.

1,136,076. Original application filed January 9,

[0 all whom it may concern:

Be it known that I, EDWIN L. WIEGAND, a citizen of the United States, residing at Canal Dover, in the county of Tuscarawas and State of Ohio, have invented a certain new and useful Improvement in Processes of Producing Electrical Heating Devices, of which the following is a full, clear, and

' exact description, reference being had to the accompanying drawings.

This invention relates to a process of propurpose the provision of a process which will enable a heating device to be produced in a particularly effective manner, reducing the cost of production and increasing the efliciency of the device or appliance.

Generally speaking the defined further and more sisting of the combinations of steps and manipulations recited in the claims hereto annexed and illustrated in the drawings acinvention may be companying and forming a part hereof,.

wherein:

Figure 1*is a vertical sectional view taken through the center of a heating device and illustratingthe mode of .use of one form of apparatus whereby the process in question can be practised; Fig. 2 is a perspective view of the tool, or that portion of the apparatus on which the conductor is wound an supported prior to its application to the of the base plate of the heating device prior to the application of the conductor thereto;

- Fig. 4 is a perspective view of the stripping plate and Fig. 5 a similar view of the'base of the tool; Figs. 6, 7 and 8 are sectional views taken through the heating element and the cooperating parts, illustrating the successive steps in the process of producing the heating device; Fig. 9 is atransverse, cross-sectional view heating device; and Fig. 10 is a detail 1n perspective of one of the pins on the tool base.

The present application isa division of my copending' application filed Jan. 9,1914,

Serial No, 811,262.

In carrying out the process illustrated and Specification of Letters Patent. v

. consistency,

it to perform its heating generally as conperspective view the use of a hydraulic press,

through the complete I Patented Apr. 20, 1915.

1914, Serial No. 811,262. 'Divided and this application filed July 13,

1914. Serial 110.850,?46.

claimed herein, I first apply to the base for a heating device a layer of material, preferably cementitious, such as is ordinarily employed for the support of the conductors of such devices. For this firstlayer, the material may be in a sufficiently fluid condition to enable it to be applied by pouring. This layer is then dried,preferablyby specially arranged surface-plates, heated preferably by steam. After this preliminary layer has been so dried, a second layer, preferably of the same kind of material, is applied to the article and is partially dried 111 the manner.described in connection with the first layer, until'it is reduced to a plastic or utty-like which renders it capa le of receiving and retaining the conductor. The conductor is given a form which will enable function in an efiicient manner. It is then introduced (preferably; by the mechanism to be described hereinafter) into the plastic second layer, the ends of the conductor being suit- 'ably arranged for connection with the source put it in condition to receive a pressure plate, which pressure plate is sub ected to a such as is obtained by with the result that a very intimate contact is obtained between the conductor and the surrounding material, homogeneous mass I and adapting the exposed surface of the material for the reception of a platewhich serves to keep in place the heating element proper (consisting of the conductor and the surrounding material) as well as covering this element for the purpose of protection. After the pressing operation, the heating element still contains a certain .amount of moisture, whichis driven out by a prelimi- I nary heating in a drying kiln, after which the whole is subjected to a heating actionvery high pressure,

'suflicient in temperature and duration to ductor, in which-case I dry the whole tothe proper degree necessitated by the requirements of the lower or insulating layer, and then by sprinkling or moistening reduce the upper part of the mass to the consistency necessary to the reception and retention of the conductor. The drying, application of the final layer, pressing, and vitrifaction proceed as before and the advantage of this modification is the entire homogeneity of the first and second layers.

In carrying out my im may and as at present a vised preferably will employ a machine of the character shown in the drawings, which machine will now be described in connection with reference characters.

1 denotes a bed of any suitable size and outline, said bed being designed to support the moving parts of the apparatus and the roved process I device to which the conductor is to be applied. For convenience of description, that part of the heating device which receives the heating element proper will bereferred to as the base. In the drawings, for purposes of illustration, the-heating device is shown as forming part of a sad iron. This base is indicated at 2 and is shown as located on. the bed in any convenient manner, as by means of gages 3 shown as secured to the plate 4. Suitably mounted above this bed is a vertically movable arm 6, to which aring 13 is pivoted upon horizontal trunnions 1 1 one of which is here shown as provided with a radial arm 38 adapted to engage either of the .latches 39 or 40, whereby it may be retained with either side uppermost. The end of the arm 6 is preferably provided with a handle 12. Aturret 17 is secured in this ringin any suitable manner as by the plate 18, the turret having a longitudinal bore 19. On the top of the turret there is secured the tool on which the conductor is wound to give it the desired shape and on which it is supported until applied to the previously prepared base 2. The tool comprises a base plate 20 therefrom a series of pins 21, the pins being arranged to support the conductor while it isbeing wound and to give to said conductor the desired symmetrical shape which will best adapt it for use in the particular heating device of which it is to form a part.

Each pin is preferably of the shape shownparticularly in Fig. 11 and has anupper reduced end 22, which reduced end projects beyond the stripping plate (to be described hereinafter), such reduced end being provided with a substantially vertical narrow having projecting" face 23 and the top of this reduced end he ng tapered to make a recess of correspondingly small dimensions when inserted in the cementitious material in the base 2. I

24: denotes a stripping plate which is mounted on the pins 21, said pins projecting through apertures 25 in the plate and,hav-' ing their reduced ends 22 projecting thereabove.

The base plate 20 is shown as provided with an aperture 26 for the reception of the stud 27. This stud is shown as provided with a threaded aperture for the reception of a screw 28 which is placed within a recess 29 in the top of the stripping plate 24. The

end of the stud 27 projects into the bore 19 and is preferably cupped, as shown at 30, for the reception of the rounded end of a push rod 32,whose other end is preferably pivoted to a lever 33 fulcrumed to the arm 6 in any suitable manner as by the bracket 34. I v

With this construction it will beseen that the turret 17 is reversible about the axis of the trunnions'l4 and alsorotatable about the axis of the ring 13, the former permitting itto be faced upwardly to receive the windings, the latter permitting the operator to swing or rotate it during the application V of the windings thereto. In use the-turretv is first located with the tool 20 facing upwardly, and the stripping plate 24 applied thereto with its stud 27 projecting into the bore 19. The conductor 35 is next wound upon the projecting tips of the pins 21 ac- .cording tothedesign found most satisfactory .in practice, taking into consideration rapidity of winding and uniformity of heating. I much prefer a conductor of. the ribbon type, and the pins are best arranged so 7 that this conductor is wound around the verthe conductor has been wound upon or ap-- plied to these pins the turret is preferably locked to the ring by suitable means (not shown) and is then inverted to the position illustrated in Fig. 1.

The base is prepared for the reception of the conductor by applying thereto the initial layer 52 of the cementitious material, this material being introduced in a more or less fluid condition. The layer isthen dried in any convenient manner, as by the application of the steam heated plate 53 thereunder. A second layer 54 of plastic material is then applied to the base, and this layer is partially dried, as by means of the steam heated plate 53, until it is in'a plastic or putty-like condition,.when its consistintroduced beneath ency adapts it best for the reception and retention of the conductor. Or I may apply at one operation. a quantity of cementitious material sufiicient for both layers and dry the whole .to the degree sufficient for the body of the material, subsequently softening the upper part by sprinkling so as to receive the conductor. In any case the fluidity of the first layeris preferably such as barely-to cause it to seek its level, and to assureits coming into intimate contact with all parts of the casing interior.

Thebase prepared as above described, is the turret 17, which is thereupon depressed by means of the handle 12 so as toembed the conductor in the plastic material. The push rod 32 is next applied and the lever-33 depressed, thereby holding down the stripping plate and raising the arm 6, thus withdrawing the pins from-the the latter embedded in the plastic material. Owing to the tapered ends 22 of the pins, the opemngs which are made in the plastic material will be of small extent and will not interfere with the production of a homogeneous filling for the base 2 and the intimate contact between such filling and the conductor. The stripping plate is then removed and the plastic material is dried, preferablyby the use of one of the plates 53. A third layer 59 preferably of cementitious material in then ap-' plied to the base 2, covering the conductor, and as this final layer is dried sufficiently so as not to be sticky or tacky a pressing plate 61 of proper shape, surface, and dimensions is applied to the surface and forced powerfully thereagainst by suitable means such as a hydraulic press, the opposed members of which are indicated conventionally at 62 and 63, Fig. 9. The result of this pressing action is to secure a very intimate contact between the conductor and the surroundingr the conductivity for heat,

cementitious material, producin a solid,

homogeneous mass, the upper sur ace whereof is adapted to receive a cover plate 64:. f the which will preferably form a part 0 heating device, and serve to keep in place the heating element (consisting of the conductor and the surrounding cementitious material). This compacting alsoexpels all air for both from the mass thus improving reduces its hydroscopic tendency, and prevents change in volume of the mass upon swiftest action, which is a very important matter owing to the necessity of having the cavity entirely filled with material and still being able to secure the cover tightly in place. After the pressing operation, the heating element still contains some moisture, which is drivenout by a preliminary heating operation, as in a drying kiln, after which this element is sub- I claim is zcovering said retention of an electric conductor; applyjected to a temperature sufficiently high and of sufficient duration to vitrify the mass n which the conductor is embedded.

While I have necessarily shownand described in detail electrical heating device may be produced by means of my process and apparatus, it will be evident that these details may be departed from, more or less, the spirit of my invention; hence I do not propose tobe limited to such details, except as they may be positively included in the claims hereto annexed or such limitation maybe rendered necessary by the state of the prior art.

Having thus described my invention what 1. The process of making electrical heating devices which comprises providing a suitable base with abed of cementitious material having its lower part of greater hardness and dryness than its upper part; inserting a heat producing element into such upthe application of pressure and vitrifymg the same by the application of heat. i

2. In a process of making electrical heating devices, the steps which consist of providing a suitable base with a bed cementitious material, inserting into. said bed a previously formed conducting coil,-

co1lwith=plastic material, abstracting moisture from said material, compacting said material, and vitrifying S316.

material.

3. The process of manufacturing electrical of plastic the manner whereby an a without avoiding heating devices which comprises providing a "suitable base with a mass of cementitious material whose outer part is softer and more plastic than its inner part; embedding an electric conductor in such softer part; applying a covering of cementitious material to said conductor; drying the mass; ing the mass tohigh pressure; and drying and burning the mass.

4.. The process of making electric heating devices which comprises applying to a subjectsuitable base a mass'of plastic cementitious material; drying the same;

softening the topmost parts thereof for the reception an ing a coveringmass of plastic cementitlous material; drying the whole mass; compacting the entire mass by the application of pressuregand finally vitrlfying the same by second mass; applying a covering of cementitious material thereto; partially drying the covering; subjecting "the mass thus formed to high pressure; heating the mass to drive out the moisture; and finally bakingor firing the mass to vitrify the same.

In testimony whereof, I hereunto affix my signature in the presence of two Witnesses. EDWIN .L. WIEGAND. Witnesses I BRENNAN B. WEsT, HAROLD E. SMITH. 

